The invention relates to an article of footwear suitable for sporting or recreational activities.
Roller boots having wheels on the bottom have given rise to a popular sporting recreational activity over recent years. The present invention is directed towards providing a personal mode of transport which is suitable for use in recreational activities.
According to one aspect of the present invention an article of footwear having a support structure, the support structure defining a lower sole formation and an upper leg portion, characterised in that a primary lever is mounted to the support structure for movement about a primary pivot, the primary lever extending from the primary pivot below the sole formation of the support structure and being biased away therefrom by resilient means; and a secondary lever being pivotally mounted to the primary lever for movement about a secondary pivot, the secondary pivot being adjacent the lower end of the primary lever, the secondary lever extending downwardly from the secondary pivot and being biased away from the sole formation of the support structure by resilient means, the second lever being pivotal relative to the first lever towards the sole formation against the biasing force of the resilient means.
According to a preferred embodiment the article of footwear is used in pairs and may be formed integrally of a pair of boots or as an attachment for a pair of boots.
Such a pair of boots can assist the human running motion, and is powered by energy which is stored and subsequently released from the resilient means, which may typically be in the form of a spring.
According to a preferred embodiment of the invention the primary lever has first and second portions, the first portion extending to one side of the primary pivot downwardly below the sole formation of the support structure and the second portion extending to the opposite side of the pivot, the resilient means acting between the second portion of the primary lever and the leg portion of the support structure. In similar manner the secondary lever may have first and second portions, the first portion extending downwardly and resilient means acting between the second portion of the secondary lever and the primary lever or the support structure.
In a preferred embodiment the primary lever comprises two generally parallel limbs disposed one on each side of the support structure and the secondary lever comprises two or more generally parallel limbs, each pivotable about the first portion of the primary lever. Each limb of the secondary lever preferably has a secondary resilient means such as a spring coupled with the support structure or with the primary lever.
For the purposes of efficiency the resilient means may be coupled to the second portion of the primary lever by a pulley.
The tension of the resilient means may be adjustable, either manually or automatically by suitable means, for example tensioning levers or by pneumatic, hydraulic or electromechanical actuators.
In some embodiments, the boot may have a plurality of primary levers each primary lever having independent resilient means. In such embodiments, it is preferred that each primary lever has an independent secondary lever pivotal mounted thereon.
In order to vary the ground purchase according to the user ""s ability, the splay of the secondary levers or the limbs of the primary lever or the or each secondary lever may be adjustable, that is, the width of separation of the secondary levers may be varied along the length of the levers.
In some embodiments either or both primary and secondary levers may be foldable or movable in order that the article of footwear may be used in a normal walking manner.
In some embodiments the primary lever may be directed in a downward direction rearwardly of the support structure.
The secondary lever may be straight or alternatively the first and second portions may be angled at, or adjacent, the secondary pivot at an angle of less than 180 degrees, such that the ends of the secondary lever contact the ground to provide the user with a stable base on which he or she might stand. The first and second portions of the secondary lever may be interconnected such that the included angle may be adjustable. The length of the second portion may also be adjustable, for example telescopic.
The movement of both the primary and secondary levers, the primary lever length and/or the point at which the resilient means is coupled to the leg portion of the support structure may be adjusted. Suitable means for adjustment may comprise ratchet winding, a one way pulley system or screw thread device for adjusting the tension of the primary and/or secondary resilient means.
The various components of the article of footwear may be comprised of carbon fibre composite. For example, the secondary lever may comprise carbon fibre composite which itself is flexible. Alternatively the secondary lever may be formed from sprung steel. The primary lever may comprise carbon fibre composite.
Additional levers may be used with the device. For example, a third lever may be used which may be positioned between the support structure and the primary lever, the third lever being pivotally attached to the support structure at one end and defining the primary pivot at the other end. Additional resilient means may act on said third lever. Additionally or alternatively an upper leg lever may be attached to the article of footwear pivoting in the knee and hip regions, and an upper leg spring may be positioned behind the upper leg or in a back pack manner. With the use of the upper leg lever, arm handles may be utilised, motion of which can increase the spring flexion or extension or may simply be used for sport.
The power of the article of footwear may be enhanced by the use of active components such as pneumatic, hydraulic or electrical means. These may be used directly on to the levers, or in conjunction with energy-saving springs by extending the length further than the normal extension so giving more stored energy or power. Sensors may be provided in the primary or secondary levers which activate the use of the active components. Alternatively, or additionally hand held switches may be used to switch on or off the active components. Such power assistance means my include energy storage means which may be charged by motion of the mechanism during use. For example movement of the primary lever may be used to pump fluid to a pneumatic or hydraulic pressure accumulator.
The article of footwear may be used in combination with a tail adaptation attached to one or more of the springs, or to the back of the wearer which acts both as a counter poise balance and as an energy store.
Sprung or weighted tails may be positioned on each article of footwear, the distance and/or weight of the tail being preferably adjustable for complying with the resonance for different running stages.
The article of footwear may have various adaptations to diversify the manner of usage. For example, roller skate wheels or ski attachments may be attached to the secondary levers. Alternatively or additionally water ski attachments, snowboard attachments, ice skate attachments or hydrofoil attachments may be used with the boot. Another adaptation comprises the use of large pneumatic wheels. In these applications the resilient means will act as shock absorbers.
The articles of footwear may be used in combination with the use of wings connected to the arms in order to prolong the stride or the jump into the air of the wearer.
Conveniently, articles of footwear are provided with a braking system. This may be provided by mean to gradually releasing tension in the resilient means, in a controlled manner.